Aircraft fitted with undercarriages bearing braked wheels are known. The braking is managed by a braking computer which delivers braking commands to power distribution devices (servo-valves for the hydraulic brakes, controlled inverters or EMACs for the electromechanical brakes) which distribute braking power (regulated pressure or current) to the brakes. The braking commands are generally generated for each of the braked wheels taking account of a command slip rate to be applied to the wheel, which is calculated by comparing the longitudinal speed of the aircraft with the estimated peripheral speed of the wheel. If a difference appears, this is the sign that the wheel is starting to lock and it is appropriate to reduce the braking command until the wheel starts to rotate again sufficiently such that the peripheral speed is equal to the longitudinal speed reduced by the slip speed calculated using the command slip rate.
The longitudinal speed of the aircraft is generally provided by the inertial system of the aircraft.